Calculating machine



Oct. 28, 1941.

Ion

E. R. BOOKER CALCULATING MACHINE Filed July 13, 1938 52 S3 51'! 55. 5G 57 58 8 8G 6 Sheets-Sheet l INVENTOR.

ATTOIUVEY Oct. 28, 1941. BQQKER CALCULATING MACHINE 6 Sheets-Sheet 2 Filed July 13, 1938 VEN TOR. 54 flomfav.

ATTORNEY 1941. E. R. BOOKER CALCULATING MACHINE F iled July 13, 1938 6 Sheets-Sheet 3 A T TURNEY.

1941- E. R. BOOKER CALCULATING MACHINE Filed July 13, 1938 6 Sheets-Sheet 4 m5 .n m

A TTORNLY.

Oct 28, 1941. E. R. BOOKER 2,260,827

' CALCULATING MACHINE Filed July 13, 1938 6 Sheets-Sheet 5 Y ATTORN Y Oct 28, 1941. E. R. BOOKER 2,260,827

CALCULATING MACHINE Filed July 13, 1938 6 Sheets-Sheet 6 INVEIGITOR.

A TTORIVEY Patented Oct. 28, 1941 UNITED STATES PATENT OFFICE CA U T G MACHINE Eugene R. Booker, San Jose, Calif. Application July 13, 1938, Serial- No. 218,985

' 2 Claims. 7 gal. 235-61) The present invention relates to calculating machines, and more particularly to machines adapted to accomplish multiplication through electric mechanical means in a mannersimilar to that disclosed in United -States1Letters Patent No. 1,870,705, issued to William'Black, i'or Calculating machine, on August 9, 1932. j 5

It is the object of the present invention'to provide a calculating machine for accomplishing multiplication employing the generalprinciples of operation disclosed in the said patent to William Black, No.1,870,705,- but being an improvement over the disclosure jo fsaid "patent in the use of certain simplified mechanisms; and electrical circuits.

It is a further object of the invention to provide an improved keyboard and key switch structure for machines of this general type. 3 1; A still further object of the invention is -the provision of an improved and simplified" selector switch for use in such a calculating machine for the control successively of a multiplicity of op-1 erations, each of which operations controls a multiplicity of electrical circuits. Another object of the invention is the provision of improved and simplified means for actuating a mechanical accumulator to effect registration thereby of a number which may be the product of numbers entered upon remotely positioned keyboards connected accumulator.

The machine of the present invention employs two key banks, one of which is a multiplier'key bank, and the other a multiplicand key bank. Each of these key banks comprises a multiplicity of like columns of keys,'each of which columns consists of keys numbered from 1 through-9, inclusive. In the operation of multiplying two numbers on the machine, the keys of one key bank are depressed to correspond to one of the numbers, and the keys on the other key bank are depressed to correspond to the other of the numbers. A single rotation of an operating handle then supplies motive power to carry the machine through the complete series of operations necessary to register on a series of accumulator dials successively the partial product obtained when each digit in the multiplier is multi plied by each digit in the multiplicand. For the purpose of illustrating the invention, the machine disclosed herein is shown as provided with two columns of keys in the multiplier key bank and two columns in the multiplicand key bank, and is thus capable of multiplying numbers of two digits only.- It is to be understood, how-- electrically with the ever, that this disclosure is simply for purposes of illustration, and that the described principle of operation and mechanical design disclosed may be extended to apply to a machine capable of operation with a multiplier and multiplicand of any desired number of digits. One form ofthe invention is. illustrated in the accompanying drawings to which reference is made in the following specification, wherein further objects and advantages of the invention'are made apparent.

In the drawingsv 1 Fig. 1v is a wiring diagram of one portion of the machine; g 4 I Fig. 2 is a wiring diagram which, when taken with Fig. l, constitutes a complete wiring diagram of amachine embodying the present invention; i I

- Fig. 3 is a front view of the control unit, of a machine, the casing and key banks being shown in section; i 1

Fig. 4 is a sectional view of the control unit taken along line IV-IV of Fig. 3;- Y

Fig. 5 is a plan view of the relay unit, the casing being shown in section, terior mechanism;

Fig. 6 is a side elevation of the Fig. -7 is a perspective view with parts'broken away of a single multi-contact relay switch of the type illustrated'in Figs. 5 and6;

Fig. 8 is a perspective view of a modified form of armature used in some of the switches illustrated in Fig 7 Fig. 9 is a plan view of the accumulator unit illustrating those parts of the machine which control electrically the actuation of the accumulator dials;

Fig.. 10 is a side elevation of the mechanism illustrated in Fig; 9;

Fig. 11 is a longitudinal section through the accumulator illustrating parts of the mechanical operating means of the accumulator and showing a single dial and mechanism associated there with;

. Fig. 12 is'a transverse section through the acrelay unit shown cumulaftor showing the mechanism employed for determining the extent to which an accumulator dial may be turned;

Fig. 13 is a perspective view of a single accumulator dial operating mechanism and associated parts for controlling the operation-of the dial;

and

Fig. 14 is a detailed view in side elevation of a dial and associated driving mechanism therefor. The machine of the present invention consists disclosing the inessentially of three units. The first, a control unit, is illustrated in Figs. 3 and 4, and the wiring diagram therefor is shown at the left-hand side of Fig. l. The second, or relay unit, is illustrated in Figs. 5 and 6, and the wiring diagram for said unit is that shown in Fig. 2. The third unit, or accumulator unit, is that illustrated in Figs. 9 to 14, and the wiring diagram of said unit is shown at the right-hand side of Fig. 1.

The three units may be housed separately and connected by suitable multiplier cables by means of plug sockets such as generally indicated at I50 in Figs. 9 and 10. Th sockets are not essential, and may be dispensed with if the three units are to be permanently located, and "thus they are not illustrated in the wiring diagram shown in Figs. 1 and 2. The control unit is placed within convenient reach of the operator, while the accumulator unit may be placedin any convenient position where the products registered therein may be easily read. The relay unit may be remotely located or placed in any position desired. It is of course to be understood that all three units may be built into a single housing, or that both the accumulator and relay units may be located at points remote from the operator and, if it is desirable, at points entirely remote from each other.

Control unit The control unit, as illustrated in Figs. 3 and 4, and as diagrammatically shown at the left-hand side of Fig. 1, comprises a double keyboard, a selector switch and reversing switches all mounted within a suitable casing such as indicated at I5I. The double keyboard consists of two identical key banks, an A key bank and a B key bank. Eachof these key banks consists of a plurality of columns of keys, two columns for each key bank being shown in the present illustration, and the keys of each column being numbered from 1 to 9 consecutively. The sufiix A will be used to designate keys in the A key bank, and the sufiix' B to designate the keys in the B key bank. Each of-the keys, as illustrated in Figs. 3 and 4, is carried by a stem I52. These stems are supported for vertical reciprocal movement through guide plates I53 and I54, said guide plates being made of a dielectric material such as hard rubber, Bakelite or the like. Each key is held in a normal position at the top of its reciprocal stroke by a compression spring I55 interposed between a collar I55 and the guide plate I54. The upward movement of each key is limited by a lateral projection I5I on its stem which contacts the bottom of the guide plate I54 through which the stem passes.

In order to retain any one key in any of the columns in a depressed position, a bar I53 is positioned below each column of keys and is supported for swinging movement about an axis parallel with its upper longitudinal edge by extensions I59 at its ends which project into suitable recesses in bearing members I68 which extend transversely of the columns of keys at opposite ends thereof. Each of the bars I58 is normally held against a stop member IGI secured to and depending from the lower side of the guide plate I54 by a spring I52, as shown in Fig. 3. The bars I58 are offset along longitudinal lines to provide inclined shoulders IE3 intermediate their edges when viewed in cross-section, as in Fig. 3, and the lower ends of the key stems I52 are providedeach with a latch lug I64 so that, upon depression of any key, the bar I58 underlying the column in which the key is pressed is caused to swing against the tension of its spring I62 until the latch I64 passes its lower edge, at which time the bar returns to normal position and, by engagement with the latch I64 of the depressed key, retains that key in its depressed position. The bars I58 are metallic and therefore electrical conductors so that each bar, as will hereinafter be pointed out, serves as a part of a switch, the bar serving as one part of the switch and the key stems, which are also metal, serving in each column as the other side of nine selectively operable switches. The depression of a key, however, does not close a circuit, but simply serves to select a circuit later to be closed by mechanism also to be described hereinafter.

Referring to Fig. 1, the bars I58 are shown as connected to wires IIlI, I02, I93 and IM, and the key stems are connected to wires 5I to 59, respectively, for th B key bank, and EH to 69, respectively, for the A key bank. Thus a connection may be established between any key wire and its corresponding bar I58, and wires IIlI, I02, I03 or I04 by depression of the key. The connection between the key stems and their respective wires may be made in any conventional manner, one suitable form of connection for this purpose being shown in Fig. 3 where wires are illustrated as soldered to the lowermost portion of the springs I55. Likewise, wires IM to I04 may be secured to the bars I58 in any suitable position (not shown) The selector switch and reversing switches which form a part of the control unit are shown in Figs. 3 and 4 and illustrated centrally of Fig. l at E, 'C and D, respectively. The selector switch E comprises eight multiple contact switches designated SI to 5-8. Each of said multiple contact switches comprises three spring arms I'IIJ (see Fig. 4) adapted to be flexed downwardly and interconnected at their ends by spacers I1 I, causing them to move downwardly together, and three relativelyrigid arms I12 positioned one directly below each of the resilient arms I10 so that upon downward flexing of the arms I'Ifl they contact all of the arms I12 simultaneously to close three separate circuits.

' In order that the machine go through the eight essential operations to complete a product of multiplication of two-digit numbers, it is necessary that the switches SI to 8-8 be successively and sequentially closed, and that no two of these switches be in closed position at the same time. In order to accomplish this closing of the switches SI to S8, a shaft I73 is supported for rotation by a hand crank H in bearings I14 carried by brackets I15. Spaced along this shaft above and adjacent the switches S--I to S-8 are collars I16, each of which carries a pin I 11, the pins being so positioned that upon rotation of the shaft each of them will contact the uppermost of one of the resilient spring arms I10, depressing it to close the multiple switch of which it is a part. The pins I" are positioned at circumferentially spaced intervals with respect to the shaft so that, upon a single complete rotation of th hand crank H, they effect successive closing of the switches SI to S8, respectively, and the timing is such that each switch is closed and permitted to open again before the next successive switch is closed.

The reversing switches are illustrated at C and D. The reversing switch C is made up of nine simultaneously operating double-throw switches, each of which nine switches comprises a central flexible switch arm I18 and two relatively stationary spring arms I19 and I80 positioned' above and below the flexible arm I18. The arms I18 of these switches are connected by a com'montransversely extending dielectric bar I8I and normally contact the arms I19'. -The re-' versing switch D comprises eight switches similar to thoseof the switch C, and each consists of a flexible spring arm I82 with a stationary arm I83 disposed above it and a stationary: arm

I84 disposed below it. The spring arms I82 are normally in contact with the upper arms I83 and are all connected by a common dielectric bar I85. During the operation of the machine, it is required that the flexible switch arms I18 of the reversing switch C be moved from their position contacting the arms I19 to positions contacting the arms I80 during the first four oper-[ ations of the selector switch. It is required likewise that the fiexible arms I82 of the. reversing switch D contact the arms I83 during the first four operations of the selector switch and then contact the arms I84 during the last four operations thereof. In order to accomplish this adjustment of the reversing switches, a pair of cam members I86, which are substantially semi-cir cular, are carried by the shaft I13, with which they are concentric, for engagement during rotation of said shaft with the bar I8I,which controls the switch arms I18. The normal position of the cams I86 is illustrated in Fig. 4. The very tops of the cams, when they are'in this position, are slightly flattened so that as the bar I8I rests upon them the switch arms I18 remain in contact with the arms I19. As the shaft I13 is rotated by means of the crank H, the cams I86 serve to lift the bar I8I upwardly, thus causing the switch arms I18 to leave the arms I19 and contact the arms I80. This position of the switches is maintained throughout one-half the cycle of the operation of the shaft I13, at which time the bar I8I drops from the ca-ms I 88 to its normal position, and the cams contact the bar I85, moving it downwardly to break the contact between switch arms I82 and I 83 and establish contacts between switch arms I82 and I84 during the next half-cycle of operation. Through the mechanism just described, the reversing switches are caused to be in one position during the operation of the selector switches S--I, S--2, S-3, and 8-4, and in the opposite position during the'operation of the selector switches S5,S 8, S1 and S8. Relay unit The relay unit is illustrated in Figs. 5 to 8, inclusive, and the wiring diagram therefor appears in Fig. 2.

relays numbered A--I to A9 andB-I to B9, all mounted in a suitable casing such as indicated at I90 by means of a pair of'bars I9I secured to brackets I92 and I93. Each of therelays A-I to A9, inclusive, and relay B9 controls a group of nine single-pole single-throw switches. Relay B--8 controls a group of eight single-pole single-throw switches, while relays B 1; B-6, B-5, B-4, B-'-3, B 2, and BI similarly control respectively seven, six, five, four, three, two and one single-pole single-throw switches. Thus a total of one hundred and twenty-six switches are employed in the relay unit in the formation ofxthe partial products obtained by multiplyingan'y digit by any other This unit comprises eighteen is less than that of the present disclosure, the

number of relays'or electromagnets necessary for their operation greatly exceeds that of the present disclosure. Likewise, the number of wires necessary to interconnect these relay switches for the purpose of selecting circuits in the manner hereinafter to be described is considerably less in the present machine than in machines where a. greater number of switches are employed.

Details of, structure of the relays AI to A9 and'.B-I to B9 are illustrated in Figs. 7 and 8. .The single-polesingle-throw switches referred to as being controlled by the relays are arranged in groups, one such group being shown in Fig. 7 as comprising three flexible switch arms I 94 with which are interposed three relatively stationary switch arms I95. Spacing blocks I98 serve to mount and maintain all of these arms in normally separated positions, and spacers I91 are interposed between the outer. ends of the arms I94 which are slightly longer thanthearms I to connect theseflexible arms for. simultaneous movement so that they will of the bar I98, all nine switches of the three.

groups will be simultaneously closed.

An electromagnet I99 controls each of the groups of relay switches. A pivoted armature 200 on each electromagnet is normally held away.

from the magnet by. a contractile spring 2I1Iv engaging one end of the armature, and at the other end of the armature, bolts 202 connect it with the bar I98. Consequently, upon energization of the electromagnet I99, the armature 200, drawn toward the magnet against the tension of the spring 20I, will eiTect closing of all switches under control of the bar I98 through the bolts 202 and bar I 98. The movement of the armature 200, under the influence ofthe spring 20I, is limited by a stop lug 205 which is secured by means of a screw, as shown, to the bracket which, supports the .electromagnets I99. While there are three groups of three switches each for relays AI to A-9 and B9, relay B8 has one switch eliminated, relay B1 has two switches eliminated, and so on, as clearly illustrated in Fig. 5. The bars I98 are employed for all of the relays with the exceptionof B-I, B 2 and B3,which have but one, two and three switches,'respectively, and consequently require only a single group of switches. 'In order to actuate these single groups of switche's,a' simplified structure is used in place of the bar I 98, this structure being illustrated in Fig. 8 wherein the armature 200 is shown as provided with an outwardly extending bracket 203 having its outer end bent at right angles, as illustrated at 204,

to contact the switch group instead of the bar to contact more than one group of switches simultaneously.

. Accumulator The accumulator unit, details of which are illustrated in Figs. 9 to 14 of the drawings, includes a set of numbered dials generally indicated at 210, as illustrated in Fig. 9, the numbers of which display the results of operation of the machine through sight openings 211 formed in the casing of the accumulator unit directly above the accumulator dials, as shown in Fig. 10. It is the function of this unit to effect rotation of these dials depending upon the particular problem of multiplication introduced into the machine by selecting for each partial operation of the machine the proper dial, that is, the units, tens, hundreds or thousands dial, and rotating said dial through a distance that is determined and limited by the values of the multiplier and multiplicand set up on the key banks of the machine.

In Fig. 14, one of the dials 210 is shown as rotatable upon a shaft 212, which shaft is common to all of the dials. It is to be understood that the peripheral surface of each dial is numbered through 9 and that the dials are interconnected by conventional mechanism in such a manner that one complete rotation of the units dial will impart one-tenth of a complete rotation to the tens dials, as is customary in an ordinary counter mechanism of this type. A mechanism typical of the type which may be used for this purpose is illustrated in the patent to C. W. Gooch, No. 1,128,679. A gear 213 is attached to one side of each dial 210 and meshes with a gear 214 mounted on a shaft 215. A pawl 216, pivoted to the side of the gear 214, is pressed by a spring 211 into engagement with an internal star gear 218. The star gear 218 is also rotatable on the shaft 215, but is fixed to a gear 219 on said shaft (see Figs. 11 and 13) for rotation therewith. The gear 219 is meshed with an arcuate rack 22!] carried by the end of an elongated arm 221 which is pivotally supported on a shaft 222. Consequently, downward swinging movement of the arm 221 about the shaft 222 carries the arcuate rack 220 downwardly and rotates the gear 219 and the internal star gear 218 secured thereto. This rotation of the star gear 218 is clockwise, as viewed in Fig.

14, so that the teeth of the star gear ride over the pawl 216 without imparting motion to the gear 214. Upon return movement of the arm 221, however, the pawl 216 will engage with the star gear and impart rotation to the gear 214 and, through gear 213, to the dial 210, the degress of rotation imparted to the dial 210 depending therefore upon the distance that the arm 221 has been moved. It is to be noted that the star gear 218 has ten points within which the pawl 216 may engage so that any movement imparted through this mechanism to the dial 210 will result in stopping the dial with one of its ten numbers centrally positioned with relation to the sight opening in the casing through which the dial is viewed.

Referring particularly to Fig. 13 which shows in perspective that part of the mechanism illustrated in Figs. 9, and 11 necessary to register the value 3" in the tens dial of the accumulator, the arm 221 is illustrated as rotatable on the shaft 222 but normally held upwardly with its outermost end in engagement with a cross member 223 by a spring 224 connected at one end to a downwardly extending finger 225 of the arm 221, and at the other end to a fixed bracket 226. Energization of an electromagnet N-2, which is one of a group of similar magnets N-1 to N-4 (see Figs. 9 and 10) draws the armature 221 of said magnet downwardly, which carries with it a finger 228 which in turn imparts downward movement to a link 229. The lower end of link 229 embraces a latch 230, which is pivoted at one end to the downwardly extending finger 225 of the arm 221, and which is provided win a. latch lug 231 at its opposite end. Beneath the latch230 a bar 232 is mounted for swinging movement on links 233 supporting it at its opposite ends and pivoted to a shaft 234. This bar 232 may be swung rearwardly through energization of a solenoid P having its armature 235 connected to the bar 232 by means of a spring 236. Thus, with the electromagnet N-2 energized just prior to energization of the solenoid P, the latch 236 will be lowered to a position with its latch lug 231 engageable by the bar 232 which, upon rearward swinging movement, will draw the latch with it and, through the finger 225, will impart downward swinging movement to the arm 221 about its pivotal support 222 and against the tension of the spring 224. The tension of spring 236 i greater than that of spring 224 so that spring 236 will be ineffective until the bar 221 is brought to a stop, at which time the resiliency of spring 236 permits a complete operation of the solenoid P, which includes full retraction of the plunger 235. The spring 235 may be dispensed with if the solenoid P is actuated by direct current, but is necessary in case alternating current is used. The spring is to be desired in all cases, however, for obtaining quiet action.

Unless interrupted in its movement, the arm 221 will be actuated by the solenoid P through the limit of its stroke, causing the dial with which it is'associated to register the value 9. In order to limit the movement of the arm 221 to a degree less than its full stroke and thereby register a value smaller than 9 on the dial, the following mechanism is employed: Referring to Fig. 13,

a stop mechanism for limiting the movement of the arm 221 is shown in the form of a vertical bar 24% positioned alongside the arm 221 and having a laterally projecting lug 241 adapted to underlie the bar 221 and limit its downward movement. The lower end of the bar 240 projects through a slot 242 in the bracket 226, and intermediate its ends a stationary transverse shaft 243 projects through an elongated vertically extending slot 244. A compression spring 245 interposed between the bracket 226 and the lug 241 normally urges the bar 240 upwardly until the bottom end of the slot 244 is in engagement with the bar 243. The bar 240 is one of a set of similar bars arranged in alignment alongside the arm 221, as shown in Fig. 11, and an identical set of bars is provided for each of the arm-s 221, of which there are four in the present illustration. as is shown in Fig. 12. The normal position of the bar 240 is at a slight angle to the vertical so that the lug 241 thereon will not interfere with downward movement of the arm 221. It is held in this position by engagement of its upper end with a slot 246 in a plate 241 which is connected by an arm 248 with the pivoted armature of an electromagnet M3, one of a group of such magnets M-l to M9, inclusive, illustrated in Figs. 9 and 10. Energization of the electromagnet M3 imparts longitudinal movement of the plate uct 24? in the units dial; second, the 8 of the product 18'? isregistered in the tens dial of the 24"! to bring the bar 240 to a verticalposition with the lug 24| thereon underlying the arm 22L Thus downward movement of the arm 22l islimited by the length of the slot 244, and as the length of slot 244 is progressively shorter, in the bars 240 controlled by the electromagnets M] to M8, respectively, selective energizationof the magnets M-l to M9 will determine the magnitude of movement of the arm 22 I, and thereby determine the distance of rotation of the dial that.

is actuated by such movement. Energization of any one of the magnets Ml to,M8 also causes the plate 24'! moved thereby to engage a flexible arm 250 of a switch generally indicated at X-3, which is one of a group of switches X-I to X-9 (see Fig. 9), thus closing the switch and completing the circuit therethrough'to the solenoid P. Electromagnets M,I to M8 actuate respectively the first eight of said switches in the man-' nerdescribed, and electromagnet M9 actuates L switch X-9 similarly, except that a plain plate 252 is substituted in place of the notched plate 241, as in the entry of the value 9 into a dial there is a fixed limit for movement of the arm 22 l. The switches X.I to X9 are connected in parallel and, if desired, a single switch might be substituted for the nine switches, employing some suitable mechanism whereby energization of any one of the electromagnets Ml to M9 would close such a switch.

In the actual operation of the machine, the electromagnets N-2 is actuated to lower the latch 230, which will later effect operation of the arm 22!, and the electromagnet M3 is actuated to position the stop member 240, which limits the movement of the arm 22 I, and it is not until both of these preliminary operations have taken place that the electromagnet M3 effects closing of the switch X3 to complete a circuit to the solenoid P. Hence there is no possibility of the arm 22l being moved before all proper selections have been made. Through the structure just described, however, there is a minimum period of delay due to the fact that the same movement which places the stop 24l under the arm 2'2l eifects closing of the switch to energize the solenoid P.

Operation thousands column. Thus an example of multiplication of the numbers 968" and 73 by the machine may be pictured somewhat as follows:

24 is the product of 3x8 18 is the product of 3 6 56 is the product of 7x8 42 is the product of 7x6 4964 is the sum of said products In the above problem, thefirst digit to be entered in the accumulator is the 4 of the prode accumulator; third, the 6 of the product 56 'is registeredin the tens dial; fourth, the 2 of the product 42 is registered in the hundreds dial; fifth, the 2 of theproduct 24 is registered in the tens dial; sixth, the 1 of the product 18 is registered in the hundreds dial; seventh, the 5 of the product 56 is registered in the hundreds dial; and eighth, the 4 of the product 42 is. registered in the thousands dial. Thus, as the entry of these values into the dials is, as aforesaid, cumulative, the dials will move to the following positions respectively upon com- ;pletition of each of the above entries:

the'last being the product of 68 and ""73.

In the example given above, in order that the 4 of the partial product 24 be registered in the 'units dial, the electromagnet N-l must be energized to insure operation of the units dial, and the electromagnet M4 must be energized to limit the movement of said dial to the equivalent of the entry of the value 4 thereon. Likewise, to register the 8 of the partial product "18? into the tens dial, theelectromagnet N'2 is energized to select the tens dial for operation, and electromagnet M--8 is energized to limit the movement of said dial to a distance corresponding to the value of 8. The same is true in each case, one of the magnets in the group Nl to Nj 4y serving to select the proper dial, and one of the'magnets in the group MI to M- 9 serving to limit the rotation of the selected dial. The structural details of mechanism employed for transmission of a number from the units dial to the tens dial, and so on, and the specificmechanism for locking the dials when they are not in operation and for preventing otherthrow upon rotation of the dials, are not disclosed herein as they formno part'of the present invention and constitute conventional mechanism, many forms of which are well-known in the art. Such a mechanism is illustrated in the patent to C. W.

Gooch, No. 1,128,679, hereinabove referred to.

To exemplify the interconnection of the abovefdescribedmechanismby electrical circuits, the example of multiplication used above will be described in connection with the wiring diagram of Figs. 1 and 2. Electrical current from a suitable source is supplied to the machine through wires 50 and I00. One side of each of the electromagnets hereinafter referred to is permanently connected with the wire 50, and energization of any of these magnets occurs upon completion of a circuit between the opposite side of the electromagnet and the wire I00. To simplify the following description, all principal wires leading from the wires 50 and I00 will be identically numbered respectively. The first step preparatory to the operation of the machine will be the depression of the keys corresponding to 73 on the A or multiplier key bank, and depression of the keys corresponding to"68 on the B or multiplicand key bank, thus selecting the circuits controlled by these four keys, which circuits will later be closed in a proper predetermined sequence. The initial part of the rotary movement of the hand crank H will, as described in connection with Figs. 3 and 4, effect closing of switch S--I of the selector switch E, and at the 1.

l cumulator.

Registration of the digit 4 of the partial product Closing of the switch SI connects wire I from the source of electrical supply with wires IOI, I02 and I05. Wire I05 thereupon transmits current to electromagnet NI in the relay unit and thus the unit of the accumulator is selected for the entry of the first digit. Wire IOI leads;

to the units column of key bank A and thereby transmits current through the key switch which has been closed by depression of key 3 to wire 63 leading to the relay unit and to relay A-3,

said unit actuating relay A-3 to close the nine;

switches controlled thereby. Referring again to switch SI, wire I00 has also been connected thereby with wire I02 so that current flows through wire I02 to the unit column of key bank B and through the closed key switch 8 thereof, the wire 58 leading to the relay unit and energizing relay B-8 to effect closing of the eight switches controlled thereby. As the reversing switch D is in its normal position, wire I00 is connected thereby with wires I0 to I8, inclusive, which lead to the relay unit. Thus with relay switches B--8 and A3 closed, current from wire I00 will flow through switch D to wire I2, and thence through relay B-8 to wire I5, through wire I5 to relay switch A3, which completes a circuit to wire 84. The wire I5 just referred to is one of a group of wires I to 45, inclusive, which serve, as illustrated in Fig. 2, to form connections between the group of relay switches A-I to A-9 and the group of relay switches .B-,-I to B-9.

Wire 84 leads back to the control unit and through switch C connects with wire I I4 leading to electromagnet M4, thus completing a circuit to and actuating said magnet. The actuation of electromagnet M4, which has been described in connection with Figs. 11 to 14, prepares the accumulator for the registration of the value 4 upon any dial which is actuated, in this case the units dial, and then closes switch X--4., to complete a circuit from wire i00 on one side of said switch to wire I20 leading to solenoid P, thus energizing said solenoid. Since electromagnet N-I has already effected selection of the units dial, and electromagnet M--4 has established a limit to the rotation of said dial, the result will be rotation of the units dial until the digit '4? appears thereon.

The progressive rotation of the operating crank H now causes release of the switch S--I, which returns to its normal position, breaking the circuit to the solenoid P as well as to the electromagnets NI and M4 in the accumulator unit and relays A3 and 13-8 in the relay unit.

Registration of the digit 8 of the partial product 18 (3x6) Continued rotation of the hand crank H now effects closing of switch 3-2, which serves to connect wire I00 with wires IOI, I04 and I05. Wire I06 leads to and thus energizes electromagnet N-2, which effects selection of the tens dial in the accumulator. Wire IOI, which leads to the units column in key bank A, transmits current through closed key switch 3 in said colunm, and thence through wire 03 to relay A--3 in the relay unit, actuating said relay to close its nine switches. Referring back to selector switch S-2, wire I04 leads to the tens column in key bank B, causing current to flow through closed key switch 6 in said column, and through wire 56 to relay B'-6, which effects closing of the six relay switches controlled thereby. As reversing switch D is still in its normal position, the wire I00 isstill connected thereby to wires 10 to I8, and reversing switch C continues to form connections between Wires 8| to 89 and III to H9, respectively. Consequently, relay switches B6 and Aihaving been closed, current flows from wire I00 through switch D to wire Ill, and thence through relay 3-6 to wire 29 which, by reasonof relay A-3 being closed, transmits current through relay A-3 to wire 83 leading back through switch C to wire I I8 which connects with electromagnet M?-8 to energize the same.

Actuation of electromagnet M'8 prepares the accumulator for the registration of the value 8 upon whichever dial may have been selected, in this case the tens dial having been selected by electromagnet N- 2. Electromagnet M8 also closes switch XB to energizesolenoid P which, upon operation, effects registration of the value 8 upon the tens dial of the accumulator.

Again the progressive movement of the hand crank H effects release of the switch S2, which returns to its normal open position, thus. deenergizing the solenoid P, the electromagnets N-2, M-8, and the relays A-3 and B-.6, all of which return to their normal position.

Registration of the digit 6 of the partial product 56 (7X8) The next selector switch to be closed is 3-3, which serves to conect wire I00 with wires, I02, I03 and I06. Wire I06 again energizes electromagnet N2 to select the tens dial. Wire I03 leads to the tens column of key bank A and through key switch 7 in said column to wire 61, which completes a circuit to relay A'I. Wire I02 leads from selector switch S--3-to the units column in key bank B through key'switch 8 in the units'column and thence through wire 58 to relay Reversing switch D still remains. in its normal position so that upon closing of the relay switch A'I and B-0, current will flow from wire I00v through switch D to wire I5 and thence through relay switch B8 to wire I2 leading to relay switch A'I which now serves to connectwire I2 to wire 86., which is connected through'switch C with wire IIB leading to electromagnet. M76. Now with N.2 and M,-6 both energized, actuation of solenoid P will effect entry of the value 6 upon the tens dial of the accumulator. It should be understood that, as the value 8 has already been entered on the tens dial, the value 6 will be. cumulative, the accumulated values entered upon the tens dial now totaling 14. Thus the. number 4 will appear on the tens dial, and the number-1 on the hundreds dial.

At the, completion of this operation, the switch S3 again opens, de-eenergizing all of the electromagnets energized by its closing, and the machine is ready for the next part of its operation.

2,260,827 Registration of the diyitz of the partial product 42 (7X6) :3 v .Selector switch S-'-4 now closes, connecting wire I withwires I03, I04, and I01. Wire I0I still in the position connecting wire I00' to wires :50 I8, while reversing switch C'remains in the "position connecting wires 8| to 89 with wires III to H0, Now therefore the current flow from wire; I00 may b'e'traced through switch D to wire "I4, and from wire I4 through relay B6 towire '21 leading to'relay A- -I, which forms a connection with wire 82 leading to switch C and, through switch C, with wire II 2 leading in turn to electro- 'magnetM-2. The actuation of electromagnet M2 prepares the accumulator for the entry of 'the value 2 into the hundreds dial, which dial has already been selected by the electromagnet N3 so that upon closing of the switch X'2, which will occur in the-same manner described inconnection with the other operations, thesolenoid P will be energized to operate the accumulator mechanism.

At this point, further rotation of the hand crank Hopens the switch S4 to de-energize the solenoid P, the electromagnets N3, M2 and the relays AI and B6, all of which return to their normal position.

Now the first half of the operation is complete; that is to say, the machine has gone through the four operations necessary to produce the four partial products of the example given above, but in each case the right-hand figure of the partial product, that is, the 4, 8, 6 and 2, is the only figure entered into the accumulator dials.

During the second half of the operation of the machine, the same general operation will transpire, except that in each case the left-hand digits of the partial products will be entered into the accumulator dials, each in its proper position; that is, the second half of the operation will comprise the entry of the values 2, 1, 5".and 4. The principal change in the arrangement of the electrical circuits, in order to make possible the next four operations of the machine, is that the positions of the reversing switches C and D are reversed. Mechanically, this is effected by the cam I06 of Fig. 4 which, upon the second half of its rotation, permits the bar ml of the reversing switch 0 to drop I and simultaneously engages and moves downwardly the bar I85 of the reversing switch D.

The effect of this, as illustrated in the wiring diagram of Fig. 1, will be to break the connection at switch C between wires 8| to 89 andwires I II to H9, respectively, and establish connection between the wire I00 and wires 8| to 89. At switch D the connection will be broken between wire I00 and wires II to I8, and connections will be established between wires II to I8 and wires I II to II 8, respectively.

Registration of the digit 2 of the partial product 24 (3X8) The selector switch S'5 is closed upon the first part of the second half-cycle of operation of the crank H and, in being closed, connects wire I00 with wires IOI, I02 and I06. Wire I06 therefore effects energization of electromagnet N-2 to select the tens dial of the accumulator. Current flows through wire IOI across key switch number 3" in the units column of key bank A through wire 63, which leads to relayA-3 to close the switches controlled thereby. Current likewise flows through wire I02 across key switch number 8 in the units column of key bank B to wire'58, and to relay B8, thus closing its switches. Now, due to the new position of reversing switches C and D, current will flow through wire I 00, through switch C to wire 84, and by way of closed relay A3 to wire I5 leading to closed relay B8. Relay switch B8 Registration ojthedigit 1 of the partial product F Selector switch S.-0 is the next to be closed and, upon being closed, connects wire I00 with wires IOI, I04 and I01. Wire I0'I energizes electromagnet N3 to select the hundreds dial of the accumulator. Wire v IOI completes a circuit through key switch 3 in the units column of key bank A and through wire 63 .to actuate relay A- -3 and close the switches controlled thereby. Similarly, wire I04 completes a circuit through key switch ,6 in the tens column of the B key banklto wire 56 leading to relay BB, which is actuated to close the switches controlled by it. With relay switches A3 and B6 closed, and reversing switches C and D in the same position as for the last operation, current will flow from wire I00 through switch C to wire 88 and thence through relay A3 to wire 29 leading to relay B6, and through said relay switch to wire II, which connects through switch D with wire III leading to electromagnet M--I. Thus electromagnets N3 and MI have been selected for entry of the value 1 into the hundreds dial of the accumulator, and immediately after operation of the solenoid P to complete this entry, the switch 8-6 is opened.

Registration of the digit 5 of the partial product 56 (7X8) The selector switch SI now closes to connect wire I00 with wires I02, I03 and I0I. Wire I0I again actuates electromagnet N3 to select the hundreds dial of the accumulator. Wire I03 leads through key switch 7 in the tens column of key bank A to wire 61 and to relay A1. Likewise, wire I02 leads through key switch 8 in the units column of key bank B to wire 58, and through wire 58 to relay B8. Now with relay switches A! and 3-8 closed, current flows from wire I00 through switch C to wire 80, thence through relay A-I to wire I2 which leads to relay B8 and connects therethrough with wire I5. Wire 15 returns through switch D to wire II5 leading to electromagnet M5. Thus with electromagnets N3 and M5 energized, actuation of solenoid P will effect entry of the value 5 in the hundreds dial, of the acby the opening of switch SI,

Registration of the digit. 4 of the partial. product 42 (7X6) Selector switch S-8 now closes" to establish'a connection between wire [00' and wires H13, H14 and H18. Wire I08 leads to and energizes electromagnet N-, thus selecting the thousands dial in the accumulator. Wire H33 transmits current through closed key switch number '7 in the tens column of the A key bank to wire 61 and to relay Al. Wire I04 likewise transmits current through closed key switch number 6 in the tens column of the B key bankto Wire 56 and relay B-B. Thus with the switches controlled by relays A-1 and B-6 closed, the current from wire 30 flows through reversing switch C to wire 82 and through wire 82 to relay A-1 which establishes a connection with Wire 2-! leading to relay B6, and from relay B-B current passes back through wire M to switch D, which connects wire 14 with wire H4 leading to and energizing electromagnet M4. Now with electromagnets N-4 and M4 closed, the solenoid P is actuated in the usual manner to enter the value 4 in the thousands dial of the accumulator.

The completion of the full cycle of operation of the hand crank H effects Opening of the switch S8 and return of reversing switches C and D to their original position so that the machine is again inreadiness for the entry on the key banks thereof of a new problem.

As each digit of the partial products of the multiplication problem taken as an example has been entered into the accumulator dials with proper respect to the column in which it should appear, and as the entry of these digits has been cumulative, the total sum of these products, 4964 which is the final product of the multiplication of 68' and '73, is presented to view on the accumulator dials; through the sight openings provided for this purpose.

Having thus described my invention, what I claim and desire to secure by Letters Patent is- 1. In a calculating machine, means for controlling. entry of successive partial products on a series, of accumulator wheels, said means consisting of eighteen multiple contact relays, nine of which control the closure of nine. electric contacts and'nine of. whichv control the closure of one to nine contacts, respectively, said multicontact relays being controlled nine by a multiplicand key bank and nine by a multiplier key bank, circuits interconnecting said contacts and reversing switches in said circuits for controlling the. operation of the accumulator wheels jointly with said relays to cause the entry upon said wheels of partial products of the values set up on said key banks, the right and left-hand components. of said products being entered separately under control of said circuits depending on the setting of said reversing switches.

2. In a calculating machine of the character described having accumulating means, means including electric circuits for actuating the accumulating means, a bank of nine switches in said circuits having nine contacts each, av second bank of nine switches in said circuits having progressively one to nine contacts each, and reversing switches for controlling said circuits whereby said circuits cause operation of said actuating means to accumulate successively righthand and left-hand components of partial products of values corresponding to closed switches in saidbanks depending on the setting of the reversing switches.

EUGENE R. BOOKER. 

